Al Jazeera has obtained exclusive access to the network of Syrian medical professionals who are trying to help the towns and cities under siege from the government in Damascus. Medical treatment for people caught up in the uprising is becoming increasingly hard to obtain, not just for injured fighters who cannot go to public hospitals for fear of arrest or worse, but for any civilian who the government suspects of helping the opposition. Opposition activists face mounting challenges as they try to treat injured fighters and civilians, while under attack. They have even smuggled entire field hospitals into the country and developed a secret network to bring in supplies. Al Jazeera's Anita McNaught reports from Idlib province in Syria.